I have a follow-up to the question posted here. I recently got a 2.3 DroidX phone, and noticed that it as well has data encryption option. I pulled an SD card from device, and noticed that folder structure is intact. I tried reading file from the SD card, which was produced by a photo application, and it was unreadable, however the file itself contained some data which was not random, which to me indicated that not the whole file was AES'ed. I was also able to put an unencrypted file on SD card which was readable afterwards.

So, the question is: does anyone know what encryption methodology is being used here, what algorithms are in place, and how strong they are against experienced attacker?

EDIT: My friend got a droid2, which also runs gingerbread 2.3.3, and it has data encryption feature too. So... is data encryption an android feature or specific to Motorola devices?